【摘要】 针对上覆0.3m粘土层、下伏1.2m饱和砂层的可液化场地,采用2×2群桩-低承台-独柱墩结构,完成了可液化场地桥梁群桩基动力反应振动台试验。结果表明:随着埋深增加,土体孔压、加速度和位移趋于减小,随着输入频率的增大,土体孔压和加速度增大,土体位移则减小;桩的加速度和弯矩反应自下而上呈现增大趋势,桩的弯矩在承台处达到最大值,且随着输入频率的增大而减小;随着埋深的增加,桩上土反力和桩-土相对位移减小,土体模量增大;随着输入频率的增大,土体模量及耗能变小。更多还原

【Abstract】 Shaking table tests on dynamic responses of pile group foundations for bridge was performed on 2×2pile group-low pile cap-single column pier system in liquefiable ground with 0.3moverlying clay layer and 1.2munderlying saturated sand layer.The test results show as follows:Firstly,the pore pressure,acceleration and displacement of soil mass decreases with increase of depth and as the input frequency increases,the pore pressure and acceleration of soil mass increase,but the soil mass displacement decreases.Secondly,the acceleration and bending moment of the pile increase from bottom to top,and the pile bending moment reaches its maximum near pile cap.As the input frequency increases,the pile bending moment decreases.Finally,with increase of depth,soil pressure and soil-pile relative displacement decrease and soil modulus presents increasing trend.Soil modulus and energy dissipation decrease as the input frequency increases.更多还原